I have a DM800 that does not work with Dolby Digital sound. The box is flashed with an image of Enigma2 from may 27 and drivers from may 26.
When selecting AC3 sound track and turn off the AC3 downmix, my Harman Kardon AVR230 receiver showing thats it receiving Dolby Digital 5.1 sound.
The sound now stuttering and comes in chunks by about 2-second intervals. With drivers from may 15 AC3 audio works on some television channels, but sounds not OK.
I have tried to switch optical input and optical cable, but the error remains... My receiver works with my Playstation 3 and AC3 sound.

Problem sort of solved....

Compability problems between DM800 and Harman Kardon AVR 230 receiver.